1. Field of the Invention
This invention pertains to the field of energy-actuated devices used to disclose conditions of deceleration. More particularly, this invention pertains to vehicular brake light systems and to circuitry that enhances normal brake indications to disclose special conditions of severe deceleration through attention-getting phenomena such as pulsation or flashing in the brake lights.
2. Description of the Prior Art
Where numerous bodies under rectilinear motion are in close proximity, provisions are generally provided to indicate front-to-rear spatial decreases through sensory perceived indicators such as buzzers, horns and lights. While this includes a broad range of vehicles such as airplanes, ships and land vehicles, it is particularly important in high-speed mass transit land vehicles such as automobiles, trucks and buses. This invention is used in them to insure positive indication of atypical decreasing vehicular distance in order to avoid unexpected collisions.
On the roads, every vehicle, powered or unpowered, is required to have rearwardly directed visual indicators, such as brake lights, that illuminate when the vehicle is decelerating through brake means actuated by the vehicle operator. Thus, the illuminating brake lights of the vehicle in front indicate to the operator of the vehicle to the rear that the spatial relationship between the vehicles is beginning to decrease and unless the operator of the rear vehicle does not take adequate precautions, the distance may reduce to dangerous closeness.
Unfortunately, typical brake light illumination shows only a single condition of deceleration; it does not indicate the degree of deceleration. Accordingly, a vehicle with its brake lights glowing may either be slowing at a rate that provides adequate notice to the operator of the vehicle to the rear to begin applying brakes and generally retard the closure rate or deceleration at such a substantial rate that ordinary application of the brakes will be insufficient to prevent a rear end collision from occurring.
The prior art has sought to enhance vehicle brake light circuitry by providing means to cause the glowing brake lights to pulsate or flash when the decelerating condition of the vehicle exceeds a limit beyond which closure rates from following vehicles exceed dangerous proportions. Two reasons, however, appear as stumbling blocks to the acceptability and commercial success of these inventions. The first is that many of them need to be interfaced with the brake pedal, hydraulic lines, clutch, speedometer cable, transmission or automobile electrical circuitry in order to function and thus require significant installation costs and often complicate the activities of other electrical components and sometimes nullify certain warranties covering other vehicle components. Manufacturers of new cars have declined to install these devices in the assembly line and the complicated installation has inhibited the retrofit or after-market industry. The second stumbling block has been the difficulty of the prior art devices to conveniently be adapted to both the one-wire brake light circuitry, where a common wire feeds both the left and right brake lamps, as well as the two-wire brake light circuitry where independent brake voltage supply wires are provided for the left and right brake lamps. The two-wire system is generally associated with American-made vehicles whereas the one-wire system is generally associated with other makes of vehicles. For the most part, none of the prior art devices is usable with both types of circuitry without substantial modification and thus none is easily installed.
As an example, U.S. Pat. No. 3,528,056 requires physical connection to the hydraulic brake lines: U.S. Pat. No. 3,665,391 requires a separate set of signaling lamps be attached to the vehicle and is not usable with the one-wire system; U.S. Pat. No. 3,748,643 requires replacement of the vehicle tail lights and connection to the brake pedal and does not have means to adjust the degree of deceleration; U.S. Pat. No. 3,760,353 is not compatible with the two-wire brake light system. U.S. Pat. No. 4,357,594 is overly complex and requires direct tie-in to the brake pedal and speedometer cable; U.S. Pat. No. 4,384,269 requires special fitting to the brake pedal: U.S. Pat. No. 4,403,210 delivers a flashing pulse train to the brake lights irrespective of the degree of deceleration: U.S. Pat. No. 4,464,649 requires intricate interconnection with the vehicle's electric system and brake pedal; and, U.S. Pat. No. 4,550,305 requires a complex interconnection between the brake, clutch and other components.
What is therefore lacking is a device that is capable of both original installation in a new vehicle and retrofit to an older vehicle, that is capable of utilization with the one-wire and two-wire brake light circuitries, that is free of requirements for interconnection to numerous components of the vehicle, and that is adjustable to various degrees of deceleration.